First off I'm still a noob, so thanks for putting up with what is probably a dumb question. Can someone explain to me what is going on in this 
              push(@{$genes{$r[0]}{$r[1]}{$r[2]}},$r[3]);

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I think it is a Hash of a Hash of a Hash of an Array, inputing data from different elements of the array @r. But why does the array reference go at the front like that, what is it doing and how does it alter the way I might .. say print things down the line? I tried to find reading material by googling for this but wasn't able to find anything in this exact format. Any information or links or whatever would be very helpful.

In reply to Hash of Hash of Array Syntax help by ZWcarp

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